The tag is present in Lintian version 2.104.328. That is the most recent version we know about.
The given package appears to be a library package, but it recommends a documentation package. Doing this can pull in unwanted (and often large) documentation packages since recommends are installed by default and library packages are pulled by applications that use them. Users usually only care about the library documentation if they're developing against the library, not just using it, so the development package should recommend the documentation instead. If there is no development package (for modules for scripting languages, for example), consider Suggests instead of Recommends.